CEL, fuel system, and PIAA quick questions

[InkWax]

Ok, easy one first. Can I hook my PIAA 1100s' Switched Power (+) to one of the fog light lines or is there a better place?

Next, Back in January my CEL light came on. Couple weeks ago I got around to having the mechanic check it out for me. When he pulled the code it was a bad O2 sensor (not suprising since they have been in for about 140k).. So, he replaces it for me and sends me on my way.

Later that night the CEL comes on again. So a few days later I take it back and have them read the code.....Too Lean / Too Rich..... Now he did say when he pulled the old O2 sensor that it was white. I talked to a friend of mine and he said that meant the engine is running too lean.

Lately, I have had troubles with hesitation and downright sluggishness in acceleration. Based on talking with my friend and reading about CEL's related to O2 sensors on the boards here, I have a feeling that my fuel system is well part of the issue.... (Fuel filter has 166k on it....and the 98 V8 XLT has 272k miles on it.....)

So, my question is.....

Do, I have them run a fuel pressure test, replace my fuel filter, and then have them retest it to see if that was the problem? Or should I just have them replace the fuel filter and then test fuel pressure? Or is there another route I should take that I am missing? (I dont have the exact codes or I would post them)

No matter what I am getting a new fuel filter....I want them to do the fuel pressure test...

Should I (after they are done "fixing" my filter etc...) toss a can of fuel injector cleaner or something like that in to help it out?

Any suggestions would be appreciated.....Thanks

InkWax

 

[Opera House]

It would be odd if you had fuel problems and only one O2 sensor indicated problems.

 

[InkWax]

Well, the last time I went in they cleared the codes for me. The CEL didnt come on again till the next time I had a problem with hesitation..... thats why I assume it to be more fuel system related than O2... I could be wrong though.....

 

[Bill Kemp]

Hooking the + OEM fog light wire to the relay is a good way to use the OEM switch. I wouldnt do it without the relay as the factory wire wont carry enough volts to make use of the PIAA brightness.
Was your mech. able to tell which O2sensor to change. I thought there were a couple at least.

 

[ga_sport4X4]

Same problem over the last couple of months.
So here is a list of repairs I have done to fix the lean problem, eratic idle and poor gas mileage:

1. Change fuel filter and air filter

2. Cleaned MAF sensor with denatured alcohol ($7)

3. Cleaned Throttle Body with denatured alcohol

4. Check for damaged 02 wires, correct connections, and if possible, for correct power signals and grounds to each of them.

5. Check plugs and wires. I changed them since they were out of the engine and they looked horrible from running lean for 3 months. The gaps in the Motorcraft +4s were not near there pre gapped spec. They ranged from .026 to .044, and most of which were in the .032-.038 range. So, make sure they are gapped to spec.

6. Check for exhaust leaks at the manifolds and especially around the O2 sensors. Easy to detect if you have been running lean for some time. There was black soot at the point at which the exchaust manifold joins the exhaust pipe. This is directly in front of the O2 sensors. A leak here causes excessive air to enter the system. At this point, your truck makes up for the high air reading by using excessive gas to try to balance the air to fuel ratio. If you useSEAFOAM, the white smoke will reveal where there are leaks are located.

7. Check fuel pressure - my fuel pressure was up to spec, so not my fuel pressure regulator or clogged fuel line. I priced a fuel pressure regulator at Ford dealership over the phone, and they wanted $415.00. This was for the FPR and some of the metal fuel lines. I laughed and so did the parts guy. He said try somewhere else and that it should run between $60 and $115.

8. Tighten the lower and upper intake manifold bolts and change the gaskets since you are in there. This is a major pain in butt if you have never done this work. It was in my case. I wanted to do everything correctly and didn't want to break anything, primarily my plastic intake. Thanks to the good write up i finished it. This took care of the eratic idle.

9. Seafoam in the brake booster and the gas tank.

My truck runs as if it were new. The gas mileage went from 10.5 mpg to 16mpg, the response is great, normal rpms through shifting points, no eratic idle at startups or once the engine has warmed up, and no hesitation. Goodluck.